680 DR in conflicts

A decade after Halaster Blackcloak secretly abducted wizards from across Cormanthyr, in return for them plundering monsters from Undermountain, the Guild of Naturalists finally work out what happened. The Guild sends an team to rescue the wizards, but they never return. The Guild quietly abandons its expeditions into the dungeon. However, all efforts to destroy the portal linking the guild's hall and Undermountain fail.[1]